In the manufacturing processes of semiconductor devices such as IC and LSI, fine process by lithography with a photoresist composition has been conventionally carried out. In recent years, ultrafine pattern formation of a sub-micron region and a quarter micron region has been required with higher integration of integrated circuits. In such a circumstance, exposure wavelength also shows a tendency to become shorter such as from g-rays to i-rays, and further to KrF excimer laser rays. Further, besides KrF excimer laser rays, development of lithography using electron beams, X-rays or EUV rays is also now progressing.
Lithography using electron beams, X-rays or EUV rays is positioned as a pattern-forming technique of the next generation or the next of the next generation, and resist compositions of high sensitivity and high resolution are desired.
In particular, for shortening the processing time of wafers, increase of sensitivity is a very important subject. However, pursuit of higher sensitization is accompanied by lowering of pattern form and resolution that is shown by limiting resolution line width, accordingly development of a resist composition satisfying these characteristics at the same time is strongly desired.
High sensitivity, high resolution and a good pattern form are in a relationship of trade-off, and it is very important how to meet these characteristics at the same time.
There are generally two types of actinic ray-sensitive or radiation-sensitive resin compositions, that is, one is a “positive” resin composition using a resin hardly soluble or insoluble in an alkali developer and capable of forming a pattern by making an exposed part soluble in an alkali developer by exposure with radiation, and another is a “negative” resin composition using a resin soluble in an alkali developer and capable of forming a pattern by making an exposed part hardly soluble or insoluble in an alkali developer by exposure with radiation.
As such actinic ray-sensitive or radiation-sensitive resin compositions suitable for lithographic process using electron beams, X-rays or EUV rays, chemical amplification type positive resist compositions primarily utilizing acid catalytic reaction are examined from the viewpoint of the increase in sensitivity, and chemical amplification type positive resist composition comprising phenolic resin having a property insoluble or hardly soluble in an alkali developer and capable of being soluble in an alkali developer by the action of an acid (hereinafter abbreviated to a phenolic acid-decomposable resin), and an acid generator as the main components are effectively used.
On the other hand, in manufacturing semiconductor devices and the like, there are requirements to form patterns having various forms such as lines, trenches, holes, etc. For meeting the requirements for forming patterns having various forms, not only positive resin compositions but also negative actinic ray-sensitive or radiation-sensitive resin compositions have been developed (for example, refer to JP-A-2002-148806 (The term “JP-A” as used herein refers to an “unexamined published Japanese patent application”.) and JP-A-2008-268935).
In forming super fine patterns, further improvements of the reductions of resolution and a pattern form are required.
For solving these problems, a method of developing an acid-decomposable resin with a developer other than an alkali developer is also proposed (for example, refer to JP-A-2010-217884 and JP-A-2011-123469).
However, it is demanded to satisfy high sensitivity, high resolution, and high line width roughness (LWR) performance in a super fine processing region at the same time on a higher order.